This paper studies how anglers in northern England invoke models of equilibrium and 'the balance of nature' in making sense of the water environments where they regularly fish, and how they use these models as norms or ideals when designing environmental management, alongside an emphasis on natural agency and unpredictability. Like other publics, anglers are shown to be a heterogeneous group in how they think about nature and their 'lay ecologies' reflect the problematic way in which equilibrium is normalised in science and policy more generally, showing similarities with professional environmental managers. But anglers are unusual publics, because their lay ecologies are put to work in collectively managing water environments, through stocking, culling and habitat management. Thus anglers' environmental knowledge practices co-produce the environments in which they develop their lay ecologies, making their models of nature and equilibrium important both conceptually and materially.